Digitrax power management

[Aikidomaster]

I am new to DCC. I have the Digitrax Empire Builder. I am thinking of using the PM42 to breakdown the layout in to smaller blocks in order in facilitate troubleshooting. My layout will eventually fill a 20 foot x 30 foot room. I know that I will need several power boosters. I have completed the first section and now am ready to start with the yard and roundhouse. My question is, how difficult is it to connect the PM42 to the current system? I know that I will have to use rail gaps to isolate each block. Will I need to do something different with the bus power wires, such as start a new bus or continue with the bus that I already have?